Interfaces
8-43
XON/XOFF Protocol Timing (RS-422)
When you select this data flow control protocol, your printer sends an XOFF signal
when it detects the following BUSY conditions:
•
Buffer full
•
Attendance error
•
Printer not in ready state
Note:
The printer sends an XOFF signal (DC3 control or X'13') to request that data
transmission end until the buffer clears. About 640 free bytes remain in the
buffer at this time. If the computer continues to send data after the printer
sends an XOFF signal, data could be lost.
Serial Errors
Your printer places an underscore character in the link buffer when it detects an error.
Some printers post a
54 Standard Serial Error
or a
54 Serial Option x Error
(x represents
the number of the serial port) the first time they detect a transmission error (parity,
overrun, or framing). The
54 Standard Serial Error
or the
54 Serial Option x Error
can be
reset from your printer operator panel or through MarkVision Professional. Refer to
your printer user documentation for more information.
If repeated serial errors occur, power the printer off and then back on to restore proper
serial operation.
The Serial errors that do not generate such an error message are:
•
Serial Break
•
Framing error received simultaneously as a Break
•
Powering on an IBM-compatible personal computer connected to the printer
XON
XOFF
XON
XMT
RXD
